<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
   <div>
       <h2>提交文案</h2>
       <a href="http://www.example.com">
    <span id="seconds">3</span>秒后系统会自动跳转，也可以单击此链接跳转
    </a>
   </div> 
   <script>
   function timing (secs,url){
       var seconds=document.getElementById('seconds');
       seconds.innerHTML=--secs;
       if(secs>0){
           setTimeout('timing('+secs+',\''+url+'\')',1000);
       }else{
           location.href=url;
       }
   };
   timing(3,'http://www.example.com');
   </script>
</body>
</html>